very possible. That's something they used to ask you when you signed up for service, what your home areacode is for the phone/service. If you don't like it, you should contact them right away about getting a different number. You usually have 48hrs or so to cancel a contract so they should cooperate with you if you get with them now.
Some people LIKE having the cellphone number in a different area code, depending on where they do business, etc. Still they should have asked you.